1. Field of the Invention
The present invention relates to a flexible support device disposed between two members provided so as to relatively displaceable to each other.
2. Related Art
A flexible support device 129 disposed between two members 110 and 120 that are provided so as to be relatively displaceable to each other as known from the related art is shown in FIG. 44. As shown in FIG. 44, a first member 120 comprises a flat annular supported part 121. A second member 110 has a columnar supported part 111 substantially orthogonal to the supported part 121 of the first member 120, and is relatively displaceable to the first member 120 in the axial direction of the columnar supported part 111.
The flexible support device 129 disposed between this first member 120 and second member 110 comprises first and second hollow flexible support parts 129a and 129b and a middle fitting part 129c integrally disposed between these flexible support parts 129a and 129b. The flexible support parts 129a and 129b are disposed substantially coaxially and are flexibly displaceable at least in the direction of this axis. The middle fitting part 129c is fit to the supported part 121 of the above-noted first member 120.
The flexible support device 129 is made from a material, such as rubber, with the specified elastic property, and is formed such that the middle fitting part 129c is a constricted neck between the flexible support parts 129a and 129b. The flexible support device 129 is then disposed with the outside circumference part of this middle fitting part 129c fit to a hole 121h in the flat supported part 121 of the first member 120.
When first member 120 and second member 110 are assembled with the supported part 111 of the second member 110 passing through the hole 121h in the supported part 121 of first member 120, and this supported part 121 is then fit to the middle fitting part 129c as described above, the flexible support device 129 is mounted between the first and second members 120 and 110 with the supported part 111 of second member 110 passing through the hollow interior of the flexible support parts 129a and 129b of the flexible support device 129. The second flexible support part 129b is thus positioned between the middle fitting part 129c and the base surface 110f of the second [first, sci] member 110. The first flexible support part 129a is free and unrestrained on one side thereof (the top side as shown in FIG. 44) at this time.
A flat end plate 112 is then fastened to the end of the supported part 111 with the first flexible support part 129a of the flexible support device 129 located between the middle fitting part 129c and end plate 112. The flexible support device 129 is thus disposed between base surface 110f of second member 110 and the end plate 112, and the total length (height) of the flexible support device 129 is thereby limited in the axial direction.
This end plate 112 acts as a load bearing plate (stop) when a load is applied in a direction compressing first flexible support part 129a, and acts to prevent the removal of flexible support device 129 when a great displacement force is applied in a direction causing supported part 121 of first member 120 to separate from the base surface 110f of second member 110. The end plate 112 is therefore typically secured to the end of columnar supported part 111 with a locking pin, threaded member, or similar means (not shown in the figure).
When a vibratory force or impact load causing relative displacement of the first member 120 and second member 110 is applied to the above-described assembly, the damping action accompanying compressive deformation within the elastic limits of the second flexible support part 129b is able to absorb the vibration component or impact load in the direction in which the supported part 121 of first member 120 approaches the base surface 110f of second member 110, i.e., downward as seen in FIG. 44. Vibration components and impact loads in the direction in which the supported part 121 of first member 120 approaches the end plate 112 on the end of supported part 111 of second member 110, i.e., upward in FIG. 44, can be similarly absorbed by the damping action accompanying compressive deformation within the elastic limits of the first flexible support part 129a. 
It will thus be obvious that the flexible support parts 129a and 129b exhibit independent damping actions depending upon the direction of an applied load.
As will be known from the above description, a separate end plate 112 must be fastened to the end of the supported part 111 with this conventional flexible support device 129 after the flexible support device 129 is mounted between the first and second members 120 and 110 by fitting the middle fitting part 129c to the flat supported part 121.
A problem with this configuration is that assembling the flexible support device is thus complicated, requiring a greater number of parts and assembly steps. This conventional design is therefore a hindrance to keeping the production cost down.
Furthermore, in the final assembled state, a conventional, typically rubber flexible support device 129 is disposed between end plate 112 and the base surface 110f of a typically plastic or metal second member 110 with the overall length (height) thereof in the axial direction limited by the end plate 112 and second member 110.
A problem arising from this configuration is that the damping action of the flexible support device 129 changes when the temperature rises a certain amount. This is due to the difference in the thermal expansion coefficients of the material used for the second member 110, including the flat supported part 111, and the end plate 112, and the material of the flexible support device 129.
Yet further, the flexible support parts 129a and 129b operate independently to damp an applied load in a conventional flexible support device 129 as described above. When a particularly large load is expected to act in one direction, the flexible support part on the side bearing the load or vibration component must be made particularly large, or a spring or other auxiliary means must be provided to assist the flexible support part.
The problem in either case here is an increase in the size and/or complexity of the flexible support device.
When the first member 120 and second member 110 move circularly relative to each other in this conventional flexible support device 129, it is difficult to achieve a smooth circular motion because a flat end plate 112 is fastened to the end of the supported part 111, and the flexible support device 129 is disposed between this end plate 112 and the base surface 110f of second member 110.
Considering these problems of the related art, a basic object of the present invention is to provide a flexible support device that is easy to assemble; has a simple, compact construction; achieves a stable damping action even when temperature rises; and enables a good, smooth circular movement.
To achieve this object, a flexible support device according to a first aspect of the present invention is disposed between a first member having a flat supported part, and a second member having a columnar supported part substantially orthogonal to the flat supported part of the first member, and being relatively displaceable to the first member in an axial direction of the columnar supported part. The flexible support device has first and second hollow flexible support parts disposed substantially coaxially and flexibly displaceable at least in the direction of this axis respectively; a first fitting part formed integrally between the first and second flexible support parts for fitting to the flat supported part of the first member; a second fitting part formed integrally to a terminal side of either flexible support part for mounting on the columnar supported part of the second member; and a movement limiting part formed integrally to one flexible support part and/or second fitting part for limiting a movement of the second fitting part. The columnar supported part passes through the hollow interior of the first and second flexible support parts. The second fitting part is mounted covering the end of the columnar supported part of the second member. When the second fitting part is so mounted, the movement limiting part engages the end of the columnar supported part, and limits movement of the second fitting part in the direction of said end.
Once the flexible support device is installed, the movement limiting part prevents the flexible support device from coming off the end of the stud or shaft on which it is mounted, and also bears an applied load. It is therefore not necessary to provide a separate end plate fastened to the end of the columnar supported part for these purposes.
When seen in vertical section, the end of this columnar supported part of the second member preferably has a partially circular profile, and the inside edge of the second fitting part also has a partially circular profile. This enables the first and second members to move relative to each other on a circular path.
Yet further preferably, a plurality of protrusions is formed on the inside surface of the second fitting part with the protrusions directed to the center of this circular profile.
These protrusions maintain a specific gap between the end and the inside surface of the second fitting part, and enable an even smoother circular motion between the first and second members.
Yet further preferably, the second member is a drive base used as a drive chassis of an optical disk drive; and the first member is a component base supported to move linearly or circularly vertically to and separately from the drive base.
In an optical disk drive of this type, the flexible support device of the invention supports the component base floating on the device base, and protects it from vibration and impact to the drive base.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.